Those who lived through the first few decades of the twentieth century in eastern Siberia experienced not just war, revolution, and foreign intervention, but also an intense period of exploration and experimentation over how regional political and territorial units should be structured. People argued for, and at times attempted to implement, states organized by ethnicity, religion, the economy, political ideology, military hierarchies, and individual and international concerns. Some rejected empire and others called for its return. Some embraced the transnational nature of the region and others sought to delineate more homogenous spaces.

Ivan Sablin's detailed and well-researched study presents this complicated story from 1911 to 1924 with a focus on the Mongolian peoples (mainly Buryat and Khalkha), who straddled the lands of the Qing and Russian Empires. The decline and fall of these empires left the region stateless and created opportunities for Mongolians and others to fill the power vacuum left behind. As Sablin rightly explains, those who sought to do so relied on a variety of available discourses to them at the time, from contemporary pan-Turkish and pan-Islamic movements, to Woodrow Wilson's call for self-determination at the end of WWI, to Buddhism and the example of the theocratic state of Tibet, to Vladimir Lenin's ideas about socialism, to traditions of Cossack militarism.

For many Mongolians, the idea of achieving some form of autonomy from a more centralized Russian or Chinese state was primary. Much of Sablin's study then illustrates how Buryat and Khalkha intellectuals worked toward this, describing their various ideas, plans, and attempts—often in competition with one another—to do so. At the same time, Mongolians were forced to contend with the territorial and political goals of larger forces at work, such as the foreign interventionists (especially Japan) and those fighting the Russian Civil War. In addition, there were powerful local actors like Grigorii Semenov and Roman von Ungern-Sternberg, who sought to carve out new states in Inner Asia loosely based on the idea that all Mongols should be united under the borders of one territory. Although Semenov and Ungern-Sternberg's ideas attracted some Mongolian autonomy seekers, the violence and chaos produced by their regimes repelled many.

While the stories of Ungern-Sternberg or Japanese intervention in eastern Siberia are more familiar, Sablin adds to our knowledge of these events by bringing in the actions of the region's Mongolian peoples. For example, he recounts the activities of Buryat political organizations that sought at various times to work with the Bolsheviks or people like Semenov. He introduces lesser-known figures, such as Lubsan Samdan Cydenov (also rendered in English as Samdan Tsydenov or Sandan Tsyden), who attempted to create a non-violent, Buddhist, theocratic, liberal state. Sablin explains how such organizations and people gained followers and built institutions of self-government. This contribution adds to our understanding of nationalist, state-building, and autonomy agendas during the Russian Civil War and demonstrates how diverse these agendas could be within the same ethnic group. All Mongolians did not simply agree on one type of political, economic, and social structure for their region.

As the Russian Civil War wound down in the west and Japanese forces retreated, the Bolsheviks began to support the creation of a newly independent state in Mongolia and the implementation of federalism in eastern Siberia. Sablin examines the formation of the Mongolian People's Republic (MPR), the temporary Far Eastern Republic (FER), and various Buryat autonomous units. When the Red Army fully gained control in 1922, the Bolsheviks liquidated the FER and created the Buryat-Mongolian Autonomous Soviet Socialist Republic. They supported the separation of the Mongols (the Buryats in an autonomous unit in Siberia and the Khalkha in the new MPR) and a federal structure for the new Soviet Union. Sablin argues that this Soviet federalism was not the result of one specific policy, but instead came about because of various internal and external forces, contemporary foreign policy goals, and the influence of many actors.

The period from 1911 to 1924 in eastern Siberia is unique because of the explosion there of so many state-building and autonomy projects. Sablin's study provides not only a guide to these projects, but analysis of the ideas and theories behind them. His research demonstrates how complicated governance can be in a transcultural space. The book offers 15 useful maps that outline the geography, economy, ethnicity, and religion of the region. A bibliography at the end of the book would have been helpful.